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Mar 28, 2018

6 min. read

As we draw closer to the passing of Bill C-45, the federal law legalizing cannabis is causing concern for many drivers on our roadways. And it’s not hard to see why. According to a study done by Public Safety Canada, of Canadians who drove impaired, 25% believe that driving under the influence of cannabis is safer than driving after consuming alcohol.

You may have even heard the rumour that cannabis can sharpen one’s ability behind the wheel. According to Dr. Robert Mann, a senior scientist at Toronto’s Centre for Addiction and Mental Health (CAMH), these opinions are not only dangerous, they don’t reflect the findings of those studying the effects of drugs on driving. Instead, they likely stem from the state of science 20 years ago when we lacked information on cannabis’ impact on driving, and the chances of being in a collision. They also explain why well-publicized articles published in science journals at the time deemed cannabis safe for drivers, adds Mann, whose focus over the past 30 years has been researching impaired driving through epidemiological and lab studies of cannabis, alcohol and other drugs.

That was then – and this is now. “The evidence today is very strong that driving under the influence of cannabis significantly increases your chances of being involved in a collision and that it’s a dangerous thing to do, as it puts you, your passengers and other road users at risk,” says Mann, who points out that 40 years ago people had the same erroneous beliefs about alcohol’s destructive impact.

Though researchers like Mann are still learning about the complexities of cannabis and how it affects us, there is enough proof that the potential for collisions increase in direct proportion to THC levels (the main intoxicant in marijuana) in our body. According to the Canadian Centre on Substance Abuse, the collision rate of cannabis users jumps from two to six times as often as drivers who aren’t impaired, depending on how much they’ve taken.

Meanwhile, the Traffic Injury Research Foundation cites a study from 2013 that found 44% of fatally injured drivers tested positive for drugs with cannabis being the most common drug found, and the Government of Canada states marijuana to be second only to alcohol as the most prevalent substance found among drivers who die in traffic crashes in Canada.

The situation only worsens when you combine two psychoactive drugs like cannabis and alcohol, a common practice for users in social situations. Mann found that people driving after taking both marijuana and alcohol tripled their collision risk compared to those who drove after taking only one.

A man driving a car with a cigarette in his hand.

Bottom line, though cannabis and alcohol can impact your brain in different ways, they both affect your attention, judgment, motor skills, reaction time, decision-making skills, balance and coordination. For those who argue they’ve been driving for years under the influence of cannabis without any consequence, that reality doesn’t dispute these findings, says Mann. They’ve just been lucky.

If you don’t want your luck to run out, approach cannabis the same way you do alcohol: avoid it completely before getting behind the wheel.

Keep in mind, if you drive while impaired, it’s not just dangerous, it’s against the law. Individuals who take cannabis and drive can face the same consequences as drivers under the influence of alcohol, including license suspension, fines, criminal charges and even jail time. In fact, drivers with a blood drug concentration over two and less than five nanograms of THC (per mililitre of blood) could face a maximum fine of $1,000 according to proposed legislation.

If you are planning on using cannabis, follow these four simple, yet potentially life-saving, rules:

  • Make sure you have a designated driver

  • Call a friend or loved one to pick you up

  • Call a cab or a ridesharing service

  • Stay over and sleep it off

With impaired driving one of the most significant road safety issues concerning CAA Members, we continue to constantly monitor the discussion over the legalization of cannabis while working hard to ensure that public education remains front and centre. It’s also why our role as a long-standing advocate for road-user safety has never been more essential.

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